Rock-drill.



PATENTBD JAN. l5', 1907,

A. H. GIBSON.

RCK DRILL.

APPLICATION FILED JULYzs. 1905.

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No. 841,139. PATENTED JAN. 15, 1907` A. H. GIBSON.

ROCK DRILL.

APPLIUATION FILED JULYzs. 1905.

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drills which are used in connection with re- UNiTnn STATES PATENT onirica.'

ARTHUR H. GIBSON, OF EASTON, PENNSYLVANIA, ASSIGNOR TO THE INGERSOLL-SERGEANT DRILL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

ROCK-DRILL.

Specification of Letters Patent.

Patented Jan. 15, 1907.

To a/ZZ whom, t may concern:

Be it known that I, ARTHUR H. GIBSON, a subject of the King of Great Britain, and a resident of Easton, in the county of Northampton and State of Pennsylvania, have invented a new and useful Improvement in Rock-Drills, of which the following is a specification.

The object of my invention is to provide certain improvements in that class of rockciprocating columns of air whereby a very large piston area is obtained without the necessity of making the whole drill-cylinder too large in diameter for convenient operation, and also to produce a structure in which the center of gravity of the piston is located farther back with regard to the shell than has heretofore been common, and also a structure wherein a reduced cushioning effect for the piston is obtained.

A further object is to provide a drill in which the several parts may be very readily assembled.

With these objects in view my invention comprises a drill Worked by reciprocating columns of air, the cylinder being provided with a plurality of piston-chambers and the piston being provided with heads fitted to reciprocate in the several chambers.

My invention further comprises means for connecting one air-tube to the corresponding rear ends of the piston-chambers and the other airtube to the corresponding front ends of the piston-chambers.

In the accompanying drawings, Figure 1 represents the drill in longitudinal central section. Fig. 2 is a transverse section taken in the plane of the line A A of Fig. 1 looking in the direction of the arrows. Fig. 3 is a fragmentary section showing a .portion of the interior of the drill-cylinder with the division-ring removed. Fig. 4 is a transverse section taken in the plane of the line B B of Fig. 2 looking in the direction of the arrows. Figs. 5 and 6 are side views and cross-sections, respectively, of the division-ring; and Fig. 7 is a view of the split locking-ring.

The shell of the drill is denoted by 1 and may be of the usual construction. The drillcylinder is denoted by 2, and it is mounted in the usual manner onthe shell 1 and is moved toward and away from its work by l the feed-screw 3. The interior of the cylinder is divided into a plurality of piston-chambers, in the present instance two pistonchambers, the front chamber being denoted by 4 and the rear chamber by 5. The drill-piston is provided with a plurality of heads corresponding to the number of piston-chambers, in the present instance front and rear heads, (denoted, respectively, by 6 and 7.) This piston is provided with a front extension 8, which passes through the front head 9 of the drill and is provided with the usual chuck 10 for the attachment of the drill-tool thereto. This piston is furthermore provided with a rear hollow extension 11, which is engaged with the rifle-bar 12, connected with the rotation device 13, of well-known and approved construction. The back head of the cylinder is denoted by 14 and forms the rear end of the back piston chamber 5. The division-ring which divides the interiorof the cylinder into front and rear piston-chambers is denoted by 15, and it is inserted into and locked in its position as follows: The periphery of the ring 15 fits snugly the inner wall of the cylinder. The ring 15 is provided with a circumferential groove 16, which is arranged to be brought into alinement with an annular groove 17 in the inner wall of the cylinder. A split locking-ring 18 of greater thickness than the depth of the annular groove 17 is arranged to lock the division-ring 15 in position. The circumferential groove 16 in the ring is of suiiicient depth for the locking-ring to be depressed entirely within the periphery of the division-ring when the same is beinginserted into position or removed therefrom.

For the purpose of releasing the divisionring 15 from its position the cylinder 2 is provided with a plurality of holes 19, communieating with the bottom of the annular groove 17, in which holes are located set-screws 20, arranged to force the split ring 18 inwardly within the periphery of the division-ring 15 or to permit the split ring 18 to expand into locking position, according to the direction in which the said set-screws are turned. In the present instance I have shown three of theseholes 19 and set-screws 20, located at equal distances around the periphery of the cylinder.

i The rear piston-head 7 is removably se- IOO IOC

cured onthe rear extension l1 of the piston, so that the said piston-head may be removed through the back of the cylinder, and thus permit the balance of the piston-to be removed through the front of the cylinder. when so desired.

A washer 21, of leather or other suitable material, is interposed between the split iront head 9 and the washers 22, which form the front end of the Jfront piston-chamber 4 of the cylinder. This washer 2l serves to prevent the leakage of air through the separationbetween the two parts of the front head.

The passages 23 24 in the cylinder 2 are attached to the air-tubes 25 26 of an air-pressor, (not shown herein,) through which tubes .air columns are caused to reciprocate for operating the drill-piston. The front ends of the iront and rear piston-chambers 4 and 5 are connected to the -passage 23 through ports 27 28, and the rear ends of the said front and rear chambers are connected to the passage 24 through ports 29 30. The Doit 28 is bifurcated, as shown clearly in Fig. 2, -for convenience in arranging -the cores in casting, to make the machine symmetrical, &c. The port 30 at the rear of the rear pistonchamber 5 is spaced a short distance from the end'of the chamber, so as to'form a cushion of air after the piston-head. 7 is moved sulficiently far tothe rear to cut oil the said port. This is the only cushioning required for the piston, as the space to the rear of the front piston-'head 6 is open at all times to the rear port 29 of the iront piston-chamber 4.

The piston-heads are so arranged on the piston that they can never hit the divisionring 15 during their reciprocating movements, but may the one hit the front head 9 and the other theback head 14.

The air-release outlet 3l and its controlling valve 32 are arranged in communication with the rear passage 24 for the purpose of letting out air after the drill stops working, so that the drill maybe easily moved by hand, and also to permit the release of air-pressure so as to permit the motor to readily restart the drill.

lIt is to be understood that any-motor for reciprocating columns of air may be used in connection with this drill-as, for instance, the electrically-driven pressor constructed and operated as illustrated in my copending application iiled April 27, 1905, Serial No. 257,736. f

What I claim as my invention is- 1.,A percussive tool-cylinder, a ydivisionring dividing the cylinder into front and rear chambers, a pistonhaving frontl and rear piston-heads, two air-pressor tubes, valveless passages leading from one air-pressor tube to the iront ends of the front and rear chambers and `valveless passages leading from the other air-pressor tube to the rear ends of the said chambers whereby the tool-piston may ybe operated by reciprocating columns of air.

2. A percussive tool-cylinder, a divisionring dividing it into front and rear chambers,

a piston-head thereon in the front chamber,

and a hollow rear extension projectinginto therear chamber, a piston-head securedfto the end of the said rear extension and arotating device having a forwardly-extended riflebar working in said hollow rear extension.

4. A percussive tool-cylinder, 4a divisionring dividing the cylinder into Jfront and rear chambers, a piston having a front extension, a piston-head thereon in the Jfront chamber and a hollow rear extension projecting into the rear chamber, a piston-head removably secured to the end of the said-rear extension and a rotating device having a forwardly-extended rile-bar working in said hollow rear extension.

5. The combination with the cylinderoi' a rock-drill, of a division-ring for separating the interior ofthe cylinder into liront and'rear piston-chambers, the inner walls of said cylinder having an annular groove thereinand the division-ring having a circumferential groove therein, a split ring located in the two grooves for locking the division-ring in the cylinder and means carried by the cylinder for forcing the split ring entirely into the groove in the division-ring for permitting'the Yremoval of the division-ring from -the cylinder.

In testimony that I claim the foregoing as my invention I have signed my'namenn presence of two witnesses, this 24th day of July, 1905.

ARTHUR H. GIBSON. Witnesses:

lI-I. D. MAXWELL, FRANK P. MCCLUSKEY.

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